Which of these is a strong base? Hc1, KOH, Mn(OH)4, Fe(OH)2

Which of these is a strong base? HCl, KOH, Mn(OH)4, Fe(OH)2

Acids = HA = HCl

Bases = BOH

The positive ion of a strong base is an alkali metal, 1st column of the periodic table.
KOH is a strong base

Mn(OH)4, and Fe(OH)2 insoluble hydroxides.